Speeding up an Internal Clock in Children? Effects of Visual Flicker on Subjective Duration

Abstract

Children of 3, 5, and 8 years of age were trained on a temporal bisection task where visual stimuli in the form of blue circles of 200 and 800 ms or 400 and 1600 ms duration, preceded by a 5-s white circle, served as the short and long standards. Following discrimination training between the standards, stimuli in the ranges 20-800 ms or 400-1,600 ms were presented with the white circle either constant or flickering. Relative to the constant white circle, the flicker (1) increased the proportion of "long" responses (responses appropriate to the long standard), (2) shifted the psychophysical functions to the left, (3) decreased bisection point values, at all ages, and (4) did not systematically affect measures of temporal sensitivity, such as difference limen and Weber ratio. The results were consistent with the idea that the repetitive flicker had increased the speed of the pacemaker of an internal clock in children as young as 3 years. The "pacemaker speed" interpretation of the results was further strengthened by a greater effect of flicker in the 400/ 1,600-ms condition than in the 200/800-ms condition.

Shortening of subjective tone intervals followed by repetitive tone stimuli

“…In contrast, the subjective duration of a test interval is lengthened when a rapid series of sounds is presented before the test interval; this was shown in the present study, as well as in some previous studies (Droit-Volet & Wearden, 2002;Penton-Voak et al, 1996;Treisman et al, 1990;Wearden, 1999). It is worth noting that the effects of tone stimuli were reversed, depending on whether the stimuli were delivered before or after the test interval.…”

“…Accumulated evidence shows that perception of a time interval is lengthened by presenting repetitive tone stimuli (Penton-Voak, Edwards, Percival, & Wearden, 1996;Treisman, Faulkner, Naish, & Brogan, 1990) or visual flickers (Droit-Volet & Wearden, 2002;Treisman et al, 1990;Wearden, 1999) before the test interval. Duration of a rapid series of tones (Burle & Bonnet, 1997;Burle & Casini, 2001;Ortega & López, 2008) or duration of a series of flickering visual stimuli (Kanai, Paffen, Hogendoorn, & Verstraten, 2006) themselves are perceived as being longer than that of a static stimulus of the same duration.…”

“…SET proposes that temporal processing consists of three major components: a clock process consisting of a pacemaker and an accumulator, a memory process consisting of short-term and reference-memory stores, and a comparator process in which decisions are made. A number of studies have manipulated the clock component of the model in both animals (Maricq, Roberts, & Church, 1981;Meck, 1983) and humans (Droit-Volet & Wearden, 2002;Penton-Voak et al, 1996) and have provided evidence for a pacemaker-accumulator clock of the type that SET proposes. However, much less attention has been devoted to the memory and decision components of the model.…”

Time perception and its neuropsychological correlates in patients with schizophrenia and in healthy volunteers

“…Weber's law in timing (the scalar property) has been reliably observed in experimental animals and humans (Droit-Volet & Wearden, 2002). Because Weber's fraction (the difference limen divided by the bisection point in the present study) is a standardised measure of performance, Weber's fractions in different conditions should be the same in each individual.…”

Time, Emotion and the Embodiment of Timing

“…The problem is that changes in tempo affect our perception of time, independently of the emotion being induced (e.g. Droit-Volet & Wearden, 2002;Treisman et al, 1990;Wearden et al, 1999). For emotional sounds, tempo and induced emotion are thus confounded variables, and their respective roles on time judgments are difficult to untangle.…”